1. Field of the Invention
The present invention relates to location of portable devices. More specifically, the present invention relates to wireless location of portable devices.
2. Background of the Invention
Today there are many portable electronic devices used by many on a daily basis. These devices are used extensively throughout the day and have become a dependency for many. Cellular telephones let users make calls from almost anywhere, allowing them to stay in constant contact. Personal digital assistants (PDAs) allow users to check e-mail and surf the internet away from the home or office. Portable music players let users listen to music on the go.
As technology progresses, these electronic devices are getting smaller and smaller. Devices once large now fit in the palm of one's hand. However, as the products get smaller, they also become easier to misplace. Frequently, a user is forced to attempt to call one's own cellular telephone to find its location. However, this does no good if the user does not even know where to begin to look, and depends on the cellular telephone having battery life remaining.
In addition to adults, kids are also using portable devices more and more. Kids all want some kind of mobile device to carry around with them, whether it's an IPOD, cellular telephone, digital camera, or any other type of mobile device. As typical with teenagers and kids, they leave them everywhere. Kids often leave devices somewhere and lose them. Half of the time they are not sure where the device is, where they left it, or what pocket it was in.
These devices are expensive, often costing hundreds of dollars. As technology has advanced, one device now performs the functions of what used to be six different devices. Many cellular telephones are now also cameras, and can be music players, PDAs, Global Positioning System (GPS) navigators, remote controllers, and portable video game systems. By losing one device a user loses the functionality of six devices.
With the size of devices, losing a device is a problem, but the theft of devices has also become much easier. A thief can pick up a small device and conceal it very easily, taking it away forever.
An RFID transmitter is an object that can be applied to objects for the purpose of identification and tracking. These transmitters are generally very small and lightweight, allowing them to be attached to objects for many different purposes. RFID transmitters send and receive radio-frequency (RF) signals to and from a reader. RFID transmitters generally contain two parts: an integrated circuit for signal modulation and storing and processing information, and an antenna for receiving and transmitting signals. RFID transmitters can be passive, active, or semi-passive. With passive RFID, the reader sends out a radio-frequency which provides enough power to the RFID transmitter for it to power up and transmit a response. Because the majority of RFID transmitters are passive and do not have a battery to power transmission, most RFID transmitters have a fairly short range. However, some transmitters can be read from several meters away and beyond the line of sight of the reader. Active RFID transmitters have an internal power source. This power source provides power to the integrated circuits to produce a powered transmission. This allows for a clearer transmitted signal with a longer range. Semi-passive RFID transmitters have their own power source, but only for powering the integrated circuit. The transmission of a signal is not powered by the power source.
Each RFID transmitter has a unique ID embedded in the signal it sends to a reader. RFID transmitters have been used in warehouses to keep track of an entire inventory for multiple stores down to every last individual product. Even a single pack of bubble gum has its own unique RFID transmitter.
What is needed is a system that allows tracking of these ever-shrinking portable devices no matter where you lose them. The system should identify every device uniquely so that, once found, a user can be absolutely certain a device is their property.